As semiconductor devices have been becoming smaller in recent years, there are cases where a semiconductor substrate is thinned to a thickness of several tens of micrometers in a step of making a semiconductor device. When thus thinned semiconductor substrate is cut and divided by a blade, chipping and cracking occur more than in the case where a semiconductor substrate is thicker, thereby causing a problem that the yield of semiconductor chips obtained by dividing the semiconductor substrate decreases.
Known as semiconductor substrate dividing methods which can solve such a problem are those described in Japanese Patent Application Laid-Open Nos. SHO 64-38209 and SHO 62-4341.
In the methods described in these publications, a semiconductor substrate having a front face formed with a functional device is inscribed with a groove by a blade on the front face side, then an adhesive sheet is attached to the front face, so as to hold the semiconductor substrate, and the rear face of the semiconductor substrate is ground until the groove formed beforehand is exposed, thereby thinning the semiconductor substrate and dividing the semiconductor substrate.